The choice of the Polish prime minister as the next European Council president will mean a new government in Poland and a sea change in domestic politics as Donald Tusk prepares to head off to Brussels.

Under the Polish constitution, Tusk's resignation as prime minister means the government as a whole has to resign. President Bronislaw Komorowski will then name a candidate for a new prime minister, who will have to secure a vote of confidence from parliament.

Tusk's ruling Civic Platform (PO) will have problems in finding a successor of similar stature to replace Tusk, who was the face of the party's successful parliamentary election campaigns in 2011 and 2007 and a dominant figure in Polish politics for the seven years he has been in power.

Some analysts have said that Tusk's departure will be a blow for the PO and will benefit his arch-rival Jaroslaw Kaczynski, head of the opposition Law and Justice (PiS) party, which is ahead in the polls in the run-up to next year's parliamentary elections.

But others say that in the short term the PO will gain as some of Tusk's aura of success rubs off on his party, particularly ahead of Poland's local elections in November.

Janusz Palikot, head of the opposition Your Movement party, said: "The PO will grow in strength over the next several months -- that's obvious, because this [the choice of Tusk for a key EU post] is a remarkable success. We [Poles] have been waiting long for such a success. This will have a positive impact on the PO."

Norbert Maliszewski, an expert on the use of PR in politics, told Polish public radio that the country's next prime minister was likely to be a woman.

Maliszewski said the strongest contenders were parliamentary Speaker Ewa Kopacz, deputy head of the PO and a long-time Tusk ally, and Deputy Prime Minister and Infrastructure Minister Elzbieta Bienkowska. The latter has earned a reputation as something of an “iron lady” figure and enjoys an exceptionally strong position in the Tusk administration.

Kopacz has admitted that she is interested in leading a new government. “If the situation requires it, then yes," Kopacz replied when asked by reporters if she was ready to take over.

Also named as contenders to replace Tusk as prime minister are Defense Minister Tomasz Siemoniak and former parliamentary Speaker Grzegorz Schetyna, once considered a dangerous rival to Tusk within the PO but sidelined by the prime minister.